1. Field of the Invention
The present invention relates to an insertion portion rigidity changeable catheter with a balloon which guides an insertion portion of an endoscope to a target site.
2. Description of the Related Art
In endoscopes for medical use, an endoscope which is inserted into tube cavities such as a gaster, and intestines has an elongated insertion portion. A tube cavity is in a shape which is curved stereoscopically and complicatedly. A bending portion which can change an orientation of an insertion portion distal end portion in, for example, a vertical direction, a lateral direction and the like is provided at a distal end side of the insertion portion of the endoscope. The bending portion performs bending motion in a desired direction by a surgeon operating, for example, a bending lever which is provided at an operation section which the surgeon grasps.
For example, in manipulation of inserting an insertion portion with a small diameter including a bending portion into a biliary tract, the surgeon inserts the insertion portion distal end portion of an endoscope to a vicinity of a biliary tract first. Thereafter, the surgeon performs a catheter introducing manipulation, a catheter fixing manipulation and an insertion portion introducing manipulation. The catheter introducing manipulation is the manipulation of introducing a catheter with a balloon into a biliary tract via the treatment instrument channel of an endoscope. The catheter fixing manipulation is a manipulation of fixing the balloon of a catheter with the balloon to a biliary tract. The insertion portion introducing manipulation is a manipulation of inserting an insertion portion into a biliary tract along the catheter with a balloon fixed into the biliary tract.
Here, the catheter introducing manipulation, the catheter fixing manipulation and the insertion portion introducing manipulation will be described.
First, the surgeon introduces an insertion portion 100 into a duodenum 110, and disposes the insertion portion 100 in the vicinity of a biliary tract as shown in FIG. 1. Next, the surgeon performs an operation of bending a bending portion 102 to cause a distal end face of a distal end portion 101 to face a tract outlet (hereinafter, described as an outlet) which is a duodenum side opening of a biliary tract 111. Thereafter, the surgeon performs the catheter introducing manipulation, the catheter fixing manipulation and the insertion portion introducing manipulation.
The catheter introducing manipulation will be described.
The surgeon leads a catheter 120 with a balloon from an opening of a treatment instrument channel (not illustrated) included in a front end face of the distal end portion 101. Subsequently, the surgeon disposes a treatment instrument distal end portion 121 in the vicinity of the outlet 112 of the biliary tract 111.
Next, the surgeon inserts a treatment instrument insertion portion 122 of the catheter 120 with a balloon into the biliary tract 111 by a predetermined amount from a distal end face of the insertion portion 100. As a result, the treatment instrument distal end portion 121 is disposed at a desired position inside the biliary tract 111.
The catheter fixing manipulation will be described.
After the surgeon disposes the treatment instrument distal end portion 121 at the aforementioned position in the biliary tract 111, the surgeon supplies, for example, air to a balloon 123 which is provided at the treatment instrument distal end portion 121. The balloon 123 inflates as shown by the broken line of FIG. 2, and the inflated balloon 123 is brought into close contact with an inner wall of the biliary tract 111. As a result, the treatment instrument distal end portion 121 of the catheter 120 with the balloon is fixed to a desired position in the biliary tract 111.
The insertion portion introducing manipulation will be described.
After the surgeon fixes the treatment instrument distal end portion 121 into the biliary tract 111, the surgeon guides the insertion portion 100 into the biliary tract 111. On the occasion of the guidance, the surgeon causes the insertion portion 100 to advance in such a manner as to be along the treatment instrument insertion portion 122 of the catheter 120 with the balloon.
However, when the insertion portion 100 is inserted into the biliary tract 111, the following difference occurs in guidance of the insertion portion 100 between in the case that the rigidity of the treatment instrument insertion portion 122 disposed in the biliary tract 111 is flexible and in the case in which the rigidity is rigid.
The rigidity of the treatment instrument insertion portion 122 being flexible refers to a state in which the treatment instrument insertion portion 122 easily bends (also described as a first flexibility). More specifically, when the treatment instrument insertion portion 122 has the first flexibility, in a state in which the insertion portion 122 is inserted through an inside of the treatment instrument channel which passes through an inside of the bending portion 102, the bending portion 102 smoothly bends into a desired bending state with an operation of the bending lever.
In contrast with this, the rigidity of the treatment instrument insertion portion 122 being rigid refers to a state in which the treatment instrument insertion portion 122 is difficult to bend (also described as a second flexibility). More specifically, the flexibility is such a flexibility that makes it difficult to change the bending portion 102 into the desired bending state shown in, for example, the aforementioned FIG. 1 with the operation of the bending lever, in the state in which the insertion portion 122 is inserted through the inside of the treatment instrument channel which passes through the inside of the bending portion 102, when the treatment instrument insertion portion 122 has the first flexibility.
In the case in which the treatment instrument insertion portion 122 which is inserted into the biliary tract 111 has the first flexibility, when the surgeon operates the bending lever (not illustrated), the bending portion 102 is brought into a desired bending state with the bending lever operation, even if the treatment instrument insertion portion 122 is in such a state as to be disposed inside the bending portion 102.
Accordingly, the surgeon can easily cause the distal end portion 101 of the insertion portion 100 to face the outlet 112 of the biliary tract 111 in the state in which the treatment instrument insertion portion 122 is disposed in the bending portion 102. In addition, the surgeon can smoothly perform the catheter introducing manipulation and the catheter fixing manipulation thereafter.
However, when the surgeon shifts to the insertion portion introducing manipulation and starts pushing of the insertion portion 100, the insertion portion 100 is not guided into the biliary tract 111, and a curved shape of the treatment instrument insertion portion 122 changes from a large curved shape R shown by the broken line of FIG. 3 to a small curved shape r shown by the two-dot chain line. More specifically, the insertion portion 100 moves in the duodenum 110 as shown by the arrow Y3 in the drawing without advancing along the treatment instrument insertion portion 122, and the treatment instrument insertion portion 122 which is inserted through the inside of the treatment instrument channel is gradually changed into a strained state.
In contrast with this, when the treatment instrument insertion portion 122 inserted in the biliary tract 111 has the second flexibility, the shape of the treatment instrument insertion portion 122 is kept to be the curved shape R. As a result, when the surgeon shifts to the insertion portion introducing manipulation, the distal end portion 101 of the insertion portion 100 is inserted to a desired position in the biliary tract 111 along the treatment instrument insertion portion 122 as shown by the two-dot chain line of FIG. 4.
However, in the catheter introducing manipulation, when the surgeon operates the bending lever in the state in which the treatment instrument insertion portion 122 with the second flexibility is disposed in the bending portion 102, the bending portion 102 cannot be changed into a desired bending shape. As a result, the distal end portion 101 of the insertion portion 100 is disposed at a position different from the desired direction of the surgeon as shown in FIG. 5, and it becomes difficult to control a protruding direction of the treatment instrument insertion portion 122.
Therefore, when the treatment instrument insertion portion 122 has the second flexibility, the necessity to change the operation procedure as shown as follows, for example, arises.
The surgeon operates the bending lever in the state in which the treatment instrument insertion portion 122 is disposed at a rear side from the bending portion 102. As a result, the distal end portion 101 faces the outlet 112 of the biliary tract 111 as shown in the aforementioned FIG. 1. Thereafter, the surgeon causes the treatment instrument insertion portion 122 to pass through the inside of the bending portion 102 which is bent to insert the treatment instrument insertion portion 122 into the biliary tract 111.
However, the treatment instrument insertion portion 122 with the second flexibility has high straightness. Therefore, when the treatment instrument insertion portion 122 is inserted into the biliary tract 111 with the aforementioned procedure, there is the fear of occurrence of the problem that the insertion portion 122 cannot smoothly pass through the inside of the bending portion 102, the situation in which the treatment instrument insertion portion 122 which protrudes from the distal end portion 101 moves in a straight line inside the biliary tract 111 as shown by the arrow Y6 of FIG. 6, or the like. When the treatment instrument insertion portion 122 moves in a straight line in the biliary tract 111, there arises the fear of the treatment instrument distal end portion 121 contacting an inner wall.
As above, in the treatment instrument insertion portion of the catheter with the balloon, the disposition enabling flexibility which enables the treatment instrument distal end portion to be easily disposed at a desired position in the biliary tract, and the guidance enabling flexibility which enables the distal end portion of the insertion portion to be guided to a desired position in the biliary tract along the treatment instrument insertion portion are required.
Japanese Patent Application Laid-Open Publication No. 2007-319668 shows a medical catheter which has a distal end portion which can be inserted into a body cavity of a patient, has a first soft catheter segment, and has a second soft catheter segment which is disposed at a distal side of the first soft catheter segment. The medical catheter is configured so as to make only the first soft catheter segment hard and soft, and is configured so as to make only the second soft catheter segment hard and soft.